Percussive tool valve



Dec. 24, 1935.

W. A. SMITH, JR., ET AL PERCUS S IVEV TOOL VALVE Filed May l0, 1954 Jf 25 za @iv Jg `A TTORNE Y Patented Dec. 24, 1935 UNITED STATES PATNT @FFlQE PERCUSSEVE @00L VALVE ginia Application May l0, 1934, Serial No. 724,886

8 Claims.

This invention relates to percussive tools and more particularly to valves therefor.

An object of the invention is to provide a valve for controlling the distribution of pressure fluid in a percussive tool, which valve is positive and quick in action, one which is thrown bylive pressure fluid from the cylinder, and one which will provide a heavy blow of the hammer piston and will materially cut down the consumption of pressure fluid in proportion to the work performed.

With these and other objects in View as may appear from the accompanying specification, the

' invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawing, showing percussive tool valves of the preferred form, and the features forming the invention will be specifically pointed out in the claims.

In the drawing:

Fig. 1 is a fragmentary longitudinal section through a percussive tool showing the improved valve therein.

Fig, 2 is an enlarged longitudinal section through the valve chest and valve showing the valve in a different position from that shown in Fig. l.

Fig. 3 is a cross section on the line 3-3 of Fig. l.

Fig. 4 is an isometric view of the valve.

Referring morer particularly to the drawing, the improved 4percussive tool or rock drill of the hammer piston type includes the cylinder I having the piston chamber l2 therein in which the piston 3 reciprocates. The piston 3 4is reciprocated by pressure fluid such as air under pressure which is initially admitted to the tool under control of the throttle Valve ll. The pressure fluid is distributed to the cylinder for operating the piston under control of the distributing Valve 5.

The distributing valve 5 comprises a body including a disc S and a ring 'l formed at the outer edge or circumference-of the disc. A bearing ring 3 is formed at the inner edge or circumference of the disc 6 and has bearing engagement with the sleeve 9 which is carried by the valve chest in and surrounds the upper end of the rifle bar il. The rifle bar il is the usual type of rifle bar mechanism employed in percussive tools Yof this type and serves to rotate the piston 3. It forms no part, however, of the present invention and therefore its construction and operation will not be specifically described.

The ring 'l of the valve 5 has transversely extending flanges i2 and i3 formed on the outer .moves rearwardly in the cylinder it will uncover edges of the ring. The flange i3 is of greater area than the flange E2. The flange l2 controls the delivery of pressure fluid to the forward end of the cylinder l by controlling the passage of pressure fluid through the passage ifi in the valve -5 chest iii and the passage i5 in the cylinder. A seat lli is formed in the valve chest l and the flange i2 seats against this seat it to cut ofi the flow of pressure fluid Vto the forward end of the cylinder. The valve 5 is shown, positioned in 1i@ Fig. 2 of the drawing to cut off the flow of pressure fluid to the forward end of the cylinder and to admit pressure fluid to the rear end of the cylinder for driving the piston forwardly.

When the valve 5 is in its rearward position, as 125 shown in Fig. 2 of the drawing the pressure fluid passes from the throttle i into the annular pressure chamber iii in the back head I9 of the drill and forwardly through the passage 20 into the passage 2l formed in the valve chest I 0. passage 2l opens into the valve receiving portion of the chest i6 between the flanges l2 and I3, through the medium of the annular channel 22. When the valve 5 is in its rearward position, the pressure fluid passes through the space 23 con- 25 trolled by the flange 24 into the valve chest and around the periphery or outer edge of the flange I3 and through passages 25 into the forward end of the cylinder for moving the piston 3 forwardly. The flange 24 is formed on the ring 'l 30' intermediate the flange l2 and i3 and it cooperates with flat surfaces 2t formed on the valve chest for cutting on the supply of the pressure fluid to either the front or the rear end of the cylinder depending upon the position of the valve, and it also co-operates with the boundaries of the annular channel 22 to provide openings through which the pressure fluid must pass on its way to the cylinder.

As the piston 3 moves forwardly during the admission of pressure fluid to the rear end of the cylinder it uncovers the port 2l in the cylinder wall which allows some of the pressure fluid to pass out of the cylinder through the passage 28 in the cylinder, passage 2li in the valve chest and against the rear side of the disc 3. When the pressure in the passage 29 has built up sufiiciently it will throw the valve 5 forwardly, moving it into the position shown in Fig. 1 of the drawing, at which time the pressure fluid passes about the flange it and into the passage ifi, through the passage l5 into the forward end of the cylinder, forwardly of the piston for moving the piston rearwardly. As the piston The 20.

the port 3G, permitting the pressure fluid to pass from the cylinder through the passage 3l in the cylinder and into the passage 32 in the valve chest, against the forward side of the disc 6. When the pressure is built up to a sufficient degree in the passage 32 it will throw or move the valve 5 rearwardly into the position shown in Fig. 2 for delivering the pressure fluid into the forward end of the cylinder and the above described cycle of operation will be repeated.

Small bleeder ports 34 communicate with the passages 28 and 3l and with the atmosphere to permit relieving of the pressure in the passages 28 and 29 and 3! and 32 when the ports 2l and 3D respectively are closed or cut off by the piston 3 so as to insure the throwing of the valve 5.

While in the drawing the flange l2 is shown as having a greater area, it is to be understood that either of the flanges I2 or I3 may have the greater area without departing from the spirit of the present invention.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown but that they may be widely modified within the invention dened by the claims.

What is claimed is:

l. In a percussive tool, the combination of a cylinder having a piston chamber and an exhaust port therein, a piston in said chamber, a valve chest having a valve chamber, inlet passages leading from the valve chamber to the piston chamber, a valve in said valve chest comprising a body including a ring, flanges at the ends of said ring for controlling the delivery of pressure fluid to said cylinder, said valve chest provided with a pressure fluid supply port for delivering vpressure fluid between said flanges, and a central flange on said ring for controlling said supply port.

2. In a percussive tool, the combination of a cylinder having a piston chamber and an exhaust port therein, a piston in said chamber, a valve chest having a valve chamber, inlet passages leading from the valve chamber to the piston chamber, a valve in said valve chest comprising a body including a ring, flanges at the ends of said ring for controlling the delivery of pressure fluid to said cylinder, said valve chest provided with a pressure fluid supplyV port for delivering pressure fluid between said flanges, and a central flange on said ring for controlling said supply port, seats formed on said valve chest, said end flanges having end seating engagement with said seats for controlling said inlet passages.

3. In a percussive tool, the combination of a cylinder having a piston chamber and an exhaust port therein, a piston in said chamber, a valve chest having a valve chamber, inletI passages leading from the valve chamber to the piston chamber, a valve in said valve chest comprising a body including a ring, flanges at the ends of said ring for controlling the delivery of pressure fluid to said cylinder, said valve chest provided with a pressure iluid supply port for delivering pressure fluid between said flanges, and a central flange on said ring for controlling said supply port, seats formed on said valve chest, said end flanges having end seating engagement with said seats for controlling said inlet passages, said central flange having edge engagement with cooperating surfaces on the valve seat and co-operating with adjacent portions of the valve seat for controlling the passage of pressure fluid to said end flanges.

4. In a percussive tool, the combination of a cylinder having a piston chamber and an exhaust port therein, a piston in said chamber, a valve chest having a valve chamber, inlet passages leading from the valve chamber to the piston 5 chamber, a valve in said valve chest comprising a body including a disc and a ring at the outer edge of the disc, flanges at the ends of said ring for controlling delivery of pressure fluid to said cylinder, said valve chest provided Ywith a pres- 10 sure fluid supply port for delivering pressure fluid between said flanges, a central flange on said ring for controlling said supply port, ports and passages in said cylinder and valve chest for delivering pressure fluid from the cylinder against 15 the opposite sides of said disc for throwing the valve.

5. In a percussive tool, the combination of a cylinder having a piston chamber and an exhaust port therein, a piston in said chamber, a valve 20 chest having a valve chamber, inlet passages leading from the valve chamber to the piston chamber, a valve in said valve chest comprising a body including a disc and a ring at the outer edge of the disc, flanges at the ends of said ring 25 for controlling delivery of pressure fluid to said cylinder, said valve chest provided with a pressure fluid supply port for delivering pressure fluid between said flanges, a central flange on said ring for controlling said supply port, 30 ports and passages in said cylinder and valve chest for delivering pressure fluid from the cylinder against the opposite sides of said disc for throwing the valve, and a bearing ring formed at the inner edge of said disc. 35

6. In a percussive tool, the combination of a cylinder having a piston chamber and an exhaust port therein, a piston in said chamber, a valve chest having a valve chamber, inlet passages leading from the valve chamber to the piston 40 chamber, a valve in said valve chest comprising a body including a disc and a ring at the outer edge of the disc, flanges at the ends of said ring for controlling delivery of pressure fluid to said cylinder, said valve chest provided with a pressure 45V fluid supply port for delivering pressure fluid between said flanges, a central flange on said ring for controlling said supply port, piston controlled ports in said cylinder, and passages and ports in said cylinder and valve chest communicating with 50 said piston controlled po-rts for delivering pressure fluid against the sides of said disc for throwing the valve.

'7. In a percussive tool, the combination of a cylinder having a piston chamber and an exhaust 55 port therein, a piston in said chamber, a valve chest having a valve chamber, inlet passages leading from the valve chamber to the piston chamber, a valve in said valve chest comprising a body including a disc and a ring at the outer edge of the disc, flanges at the ends of said ring for controlling delivery of pressure fluid to said cylinder, said valve chest provided with a pressure fluid supply port for delivering pressure fluid between 65 said flanges, a central flange on said cylinder, and passages and ports in said cylinder and Valve chest communicating with said piston controlled ports for delivering pressure fluid against the sides of said disc for throwing the valve, one of said end flanges being of larger area than the other end flange.

8. In a percussion tool, the combination of a cylinder having a piston chamber and an exhaust port therein, a piston in said chamber. a valve I chest having a. valve chamber, inlet passages leading from the valve chamber to the piston chamber, a. valve in said valve chest comprising a body including a ring, flanges at the ends of said ring for controlling the delivery of pressure fluid to said cylinder, said valve chest provided with a. pressure uid supply port for delivering pressure fluid between said anges, and a central flange on said ring for controlling said supply port, one of said end anges being of larger area, than the other end flange.

WILLIAM A. SMITH, J R. HERMAN J. SCHORLE. 

